Gyroscopically actuated electric switches



United States Patent .ce

3,522,395 GYROSCOPICALLY ACTUATED ELECTRIC SWITCHES Walter W. H. Clarke, Eversley, England, assignor to C. B.

Associates Limited, London, England, a British com- Filed Dec. 9, 1968, Ser. No. 782,403 Int. Cl. H01l1 35/14 U.S. Cl. 20d-61.45 4 Claims ABSTRACT OF THE DISCLOSURE The invention relates to gyroscopically actuated electric switches and in particular to such switches which are intended to provide a switching action in a projectile having a high speed of rotation when the projectile changes its velocity and/ or orientation suddenly, as upon impact.

The present invention relates to gyroscopically actuated electric switches and in particular to such switches which are intended to provide a switching action in a projectile having a high speed of rotation when the projectile changes its Velocity and/ or orientation suddenly, as upon impact.

Switches are known which are actuated upon changes in motion of a projectile. Thus one known type of switch employs a magnetically retained element and another known type employs a spring retained mass. Both these known types are expensive although each has certain inherent advantages. The present invention seeks to provide a switch which retains the best features of the above two known switches and which is less expensive to manufacture.

According to the present invention there is provided a gyroscopically actuated electric switch characterised by a double frusto-conical member, one portion thereof being inverted with respect to the other portion thereof, an annular member freely mounted upon the double frustoconical member to sit in the reduced diameter portion of the double frusto-conical member at the junction of the two portions thereof upon rotation of the switch as a whole, the double frusto-conical member forming one contact of the switch, a second contact being located spaced from and adjacent one end of the double frustoconical member and electrically insulated therefrom, the second contact being so dimensioned that upon a precession of the annular member about the frusto-conical member upon a change in torque applied to the switch the annular member bridges the two contacts to thereby close the switch.

Preferably the inner face of the annular member is formed as a knife edge which sits in the reduced diameter portion of the double frusto-conical member at the junction of the two portions thereof. In order to establish a good electrical contact the annular member, the double frusto-conical member and the second contact may be gold plated. The second contact may be in the form of a plane disc arranged at one end of the switch at right angles to the longitudinal axis of the double frusto-conical member. The double frusto-conical member itself may be formed with an integral base of diameter substantially equal to the diameter of the second contact or alternatively the double frusto-conical member may be xedly mounted upon such a base. The second contact and the base are spaced apart and electrically isolated one from the other by an annular spacer. The switch so formed may be encapsulated within a resin, plastics or like material.

The invention will be described further, by way of 3,522,395 Patented July 28, 1970 example, with reference to the accompanying drawings in which:

FIG. 1 is a cross-section through one embodiment of a gyroscopically actuated electric switch; and

FIG. 2 is a cross section through a part of a second embodiment of such a switch.

A double frusto-conical member 1 is formed integral with a rear plate 2. The plate 2 is secured, as by soldering at 3 to an outer ring 4. Insulation members 5 and 6 space the member 1 and the ring from a front plate 7. The whole is maintained by an encapsulation 8 of resin, plastics or like material.

An annular ring 9 is freely mounted upon the double frusto-conical member 1, the inner face of the ring being formed as a knife edge. The member 1, the plate 2, the plate 7 and the ring 9 may be gold plated to provide good electrical contact. Electric connections 10 and 11 are made to the plate 7 and the plate 2 respectively.

The normal position of the annular ring is shown in full outline and the connections 10 and 11 are insulated one from the other.

In use, with the switch mounted within a projectile for example, the knife edge will tend to position itself at the junction of the two frusto-conical members when the projectile is spinning, since the ring 9 will take up the spin of the remainder of the switch. The double frustoconical member around which the ring 9 gyrates forms one side of the switch, the other side of the switch being formed by the plate 7 which is isolated from the member 1 by the insulators 5 and 6.

During the spin of the switch about an axis coincident with or parallel to its own longitudinal axis the ring 9 will remain substantially normal to the axis of spin. However, upon a deceleration a couple will be applied to the ring `9 through its point of contact with the double frusto-conical member 1, which will result in the ring twisting about an axis across its diameter and through its point of contact with the double frusto-conical member 1.

When this occurs the ring 9 takes up the position represented by dotted outline in the drawing. Connection is now made between the member 1 and the plate 7, and thus between the connections 10 and 11 to complete an electric circuit. I

Alternatively, if the deceleration is negligible. but there occurs a change in the orientation of the spin, then the ring l9 will tend to remain spinning about its original direction of travel and will therefore again close the switch.

FIG. 2 shows an alternative construction in which an annular ring 19 is freely mounted about a support member 20 having a concave surface 21. In this embodiment the inner face of the ring 19 is rounded. Otherwise, the construction and operation of the switch shown in FIG. 2 is the same as that described with reference to FIG. 1.

I claim:

1. A gyroscopically actuated electric switch characterised by a support member having a tapered waist portion, an annular member freely mounted about the support member to sit in the tapered waist portion upon rotation of the switch, a first switch contact formed by the support member, a second switch contact being located spaced from and adjacent one end of the support member and electrically insulated therefrom, the second contact being so dimensioned that upon a precession of the annular member about the support member upon a change in torque applied to the switch, the annular member bridges the two contacts to thereby close the switch.

2. A gyroscopically actuated electric switch characterised by a double frusto-conical member, one portion thereof being inverted with respect to the other portion thereof, an annular member freely mounted upon the double frusto-conical member to sit in the reduced diameter portion at the junction of the said two portions of the double frusto-conical member upon rotation thereof, a first switch contact formed by the double frusto-conical member, a second switch contact being located spaced from and adjacent one end of the double rusto-conical member and electrically insulated therefrom, the second contact being so dimensioned that upon a precession of the annular member about the double frusto-conical member upon a change in torque applied to the switch, the annular member bridges the two contacts to thereby close the switch.

3. A gyroscopically actuated electric switch according to claim 2 in which a knife edge is formed around the inner face of the annular member.

4. A gyroscopically actuated electric switch according to claim 2 in which the second contact comprises a plane disc arranged at right angles to the longitudinal axis of the double frusto-conical member.

References Cited UNITED STATES PATENTS ROBERT K. SCHAEFER, Primary Examiner R. A. VANDERHYE, Assistant Examiner 

